Assessment of gas generation and energy recovery from municipal solid waste in Kanpur city, India.

The study reported herein presents the methane generation potential from municipal solid waste (MSW) generated in Kanpur city using four established methods, namely: the IPCC Default Method (DM), EPER Germany, The IPCC First Order Decay (FOD) method, and the Modified Triangular Method (MTM). Results revealed that the average maximum and minimum emissions with respect to total MSW generated and considered over the study period were obtained in the IPCC Default Method (19.17Gg/year) and the MTM (1.00Gg/year), respectively. Furthermore, the sensitivity analysis carried out revealed that the MTM method is the least uncertain method in predicting the methane emissions. Energy generation using the Yedla method and the Stoichiometric method was also carried out, highlighting the potential for energy recovery using methane emissions. The total energy generation potential using the Yedla method over the entire study period was determined to be 924 TJ, with an increased potential of 30% between the periods of 2022 to 2031. According to the study, there exists significant potential for effectively managing the greenhouse gas emissions from open dumpsite by harnessing the methane produced and using it for energy generation.

Efficiency evaluation of sewage treatment plants in Delhi, India, using tolerance-based data envelope analysis.

Correct and effective performance evaluation of wastewater treatment plants is a tough task because of the complex biological, physico-chemical, and biochemical processes and associated variables affecting their performance. Conventionally, the efficiency of sewage treatment plants (STPs) are obtained using some index relating pollutant removal efficiency with energy used or costs. These indicators consider only one variable at a time. This leads to incorrect assessment of efficiency, which in turn could adversely affect decision-making of the regulatory authorities. The data envelope analysis (DEA) method utilizes a Linear programming technique which can handle multiple input/output variables without requiring the cost function. This makes it an appropriate tool for assessing the relative efficiency of treatment plants. The present study assess the efficiency of 30 STPs in Delhi, India, using the tolerance-based DEA model utilizing the variable return of scale (VRS). The uncertainty was incorporated into the model using the tolerance measure. The model is solved using the "Add on" option in spreadsheet toolbox of excel solver. Results reveal that out of the 30 plants considered for the study, 6 are performing well (20%). Further, it was observed that a slight change in the input data leads to instability of the efficiency results. Lastly, the ranking is used to determine the treatment plant with best efficiency under all scenarios for the larger period of the year. Such studies will help in chalking out the best management practices that could be adopted by other regulatory authorities.

Exposure assessment of PM2.5 in temple premises and crematoriums in Kanpur, India.

Regular use of incense and earthen lamps in temples leads to the release of particulate matter (PM), airborne flecks, and gaseous pollutants. Similarly, the cremation of dead bodies using timber and other accessories such as incense, organic chemicals containing carbon, and clothes generates air pollutants. It is currently unclear how much emissions and exposure these activities may lead. This work attempts to fill this gap in our understanding by assessing the associated emissions of PM2.5 and the corresponding exposure. Ten temples and two cremation grounds were considered for the sampling of PM2.5. The average PM2.5 concentration at the ten temples and the two crematoriums was found to be 658.30 ± 112.63 µg/m3 and 1043.50 ± 191.63 µg/m3, respectively. The range of real-time PM2.5 data obtained from the nearest twelve stations located in the vicinity was 113-191 µg/m3. The exposure assessment in terms of deposition dose was carried out using the ICRP model. The maximum and minimum total respiratory deposition dose rate for PM2.5 for temples was 175.75 µg/min and 101.15 µg/min, respectively. For crematoriums, the maximum and minimum value of same was 252.3 µg/min and 194.31 µg/min, respectively, for an exposure period of 10 min.